At present, inductive boost converters are widely employed in supplying power to white light emitting diodes (LEDs), the white light emitting diodes can provide backlight to liquid crystal display (LCD) panels of battery-powered systems. The output voltage of an inductive boost converter is higher than the input voltage, including an inductor, a diode, a capacitor and a control switch, turning off the control switch can cause soar of currents passing the inductor; turning on the control switch can cause currents flow into the output capacitor through the diode. Since the capacitor stores currents from the inductor, the voltage of the output capacitor increases after several switch cycles that makes the output voltage higher than the input voltage. However, as soon as the diode is shorted, a vast amount of charges stored in the output capacitor will flow backward into the input terminal through the inductor. Taking the example of a pulse-width modulation (PWM) generator to explain the input terminal, the PWM generator is embedded with an integrated circuit, the integrated circuit in the PWM generator will be burnt down by the charges flowing backward into the input terminal so that the PWM generator cannot work properly, such as smoke and fire, which can be regarded as hidden risks.